Dynamo-electric machine.



A. H. NEULAND.

DYNAMQELECTRIC MACHINE. APPLICATION FILED IuLYII.`I9I4.

Patented Apr. 4, 1916.

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A. H. NEULAND.

DYNAMO ELECTRIC MACHINE. APPLICATIONHLED JuLY11.1914.

Patented Apr. 4., 1916.

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ALFONS H. NEULAND, OF SAN FRANCISCO, CALIFORNIA.'

DYNAMIC-ELECTRIC MACHINE.

Specification of Letters Patent.

Patented Apr. 4., 1916.

Application led July 11, 1914. Serial'No. 850,418.

To all iii/1.0m t may concern:

Be it known that I, ALFoNs II. NEULAND, a' subject of the Czar ofRussia, and a resident of the city and county of San Francisco, State ofCalifornia, have invented certain new and useful Improvements inDynamo-Electric Machines, of which the following is a speciiication.

The invention relates to dynamo electric machines and particularly tosuch machines of the commutating type.

One of the objects of the invention is to provide a dynamo electricmachine which will generate alternating current either single phase orpolyphase, having a high frequency relative to the rotation of themember generating the current and commutate such currents either todirect currents or currents of lower frequency.

Another object of the invention is to provide such a machine which maybe used as a direct current motor or generator, or as an alternatingcurrent low frequency motor or generator.

A further object of the invention is to provide such a machine by whichalternating current, either single phase 0r polyphase, may be convertedto either a direct current or to an alternating current having arelatively low frequency, or by Which a direct current or an alternatingcurrent of klow frequency may be converted to an alternating current ofhigh frequency.

Another object of the invention is to provide a dynamo electric machinewhich has a high weight eificiency and a high electrical efliciency.

In accordance with my invention I provide a machine having a toothedstator and a toothed inductor, the number of teeth on the two elementsbeing different, whereby they are alined at a plurality of portions andnon-alined at a plurality 4of portions, the alined and non-alinedportions having a. greater angular' velocity than the rotor. therebyproducing a progressive fluX having a high angular velocity. There isalso provided an armature winding which is cut by the progressing flux,inducing therein an alternating current having a very high frequencyrelative to the rotation of the rotor, and commutating means consistingof a series of conducting elements connected to the armature winding,and a series of conducting elements relatively movable With genericinvention, but it is to be understood that I do not limit myself to suchform because my invention may be embodied in a multiplicity of forms,each being a species of my said invention. It is also understood that bythe claims succeeding the description of my invention, I desire to coverthe invention in whatever form it may be embodied.

Referring to said drawings: Figure 1 is a vertical section of one formof the ma-` chine of my invention. Fig. 2 is a cross section somewhatdiagrammatic of the machine shown in Fig. l, showing one form ofarrangement of the induction windings, and a few of the connectionsbetween the coils of the winding, the connected coils being shown inheavier lines. Fig. 3 is a diagrammatic representation of thearrangement of the windings commutator segments and brushesin themachine shown in Fig. l. Fig. et is a diagrammatic representation of thearrangement of the windings and commutator segments of a modified typeof machine and the brushes of one polarity. Fig. 5 is a similar viewshowing the arrangement of the brushes of the opposite polarity, and thealternating current connections. Fig. 6 is a side view of the commutatorshowing the position of the 'two sets of brushes. Fig. 7 is adiagrammatic representation of a modified form of brush arrangement,showing the brushes of one polarity. Fig. 8 is a. similarview showingthe arrangement of the brushes of the other polarity. Fig. 9 is a sideview of the commutator showing the position of the two sets of brushes.Fig. 10 is a cross-section of they machine, somewhat diagrammatic,showing one form of construction which may be employed for producingalow frequency alternating current, only a few .of the connectionsbetween the coils being shown for the salie of clarity, as in F ig. 2.Fig. 11 is a diagrammatic representation of the arrangement of thewindings and commutator segments of the machine shown in Fig. 1, thebrushes being arranged for a two phase current. Fig. 1Q is a similarrepresentation showing a three phase brusa arrangement.

rlhe machine of my invention may be employed either as a motor or agenerator, but for the purposes of description herein I shall describeits operation as a motor.

The machine may be employed for many different purposes, some of whichwill be described hereinafter, and the construction and arrangement ofthe parts varies somewhat with the different uses to which the machineis to be put. l/'Vhen used as a direct current motor or gene ator, or alow frequency alternating current motor or generator, for example, thecollectorl rings and their associated brushes and leads are dispensedwith, but when used as a converter for example, the collector rings andtheir associated elements are employed. By varying the number of coils,commutator segments and brushes in the direct current arrangement, analternating current of low frequency may be collected at the commutatorbrushes.

The apparatus comprises a laminated stator element 2 provided on itsface with a plurality of teeth or projections 2a, which are preferablyregularly spaced. The stator element is supported in a housing 3 whichis provided with bearings et for the rotor shaft 5. Secured to the rotorshaft 5 is the inductor member or rotor which comprises the iron core 6and the laminated annular rotor element 7 which is provided on its faceadjacent the toothed face of the stator with a plurality of teeth orprojections 8, which are preferably regularly spaced. The number ofteeth on the stator diers from the number of teeth on the rotor, so thatthe I teeth are radially alined at a plurality of portions and arenon-alined at a plurality of intermediate portions. The diierence in thenumber of teeth on the two elements determines the number of points ofalinement, and in the construction illustrated I have shown a differenceof two teeth, which produces two alined portions. y

Arranged preferably on the rotor and preferably embedded between theteeth thereon are the coils 9 of the armature winding, which may bearranged in any desired manner in accordance with the usual practice,there being as many coils in the armature winding in the D. C. type ofmachine as there are teeth on the stator, or, in the present instance,there being two less coils in the winding than there are teeth on therotor. In the construction shown in Figs. 2, 11 and 12, I have employeda. series armature winding, but any other type of winding may beemployed.

Secured to the rotor shaft 5 is a hub 12 upon which are arranged thecommutator segments 13 which are suitably insulated from each other,there being as many segments as there are coils. The coils are connectedto the segments in the usual manner, the connection varying with thetype of winding employed. Contacting with the commut-ator 1l arebrushes, whose number and position will hereinafter be set forth.

The core 6 which carries the toothed rotor element 7 is provided, withinthe circle of the rotor, with a concentric cylindrical projection 15which extends into a cylindrical projection 1G on the housing. lviountedon the cylindrical projection 1G is the magnetizing coil 17, themagnetic circuit of rwhich includes the housing, the projections 15 and16; the periphery of the core G, the toothed rotor element and thetoothed stator element, the magnetic i'iux passing principally throughthose portions of the machine at which the teeth are alined.

In the machine herein illustrated, I have employed a stator havingtwenty-nine teeth and a rotor having thirty-one teeth, such anarrangement producing two alined portions and two intermediatenon-alined portions. In this arrangement there are two portions ofalinement, 180o apart, between the rotor and stator teeth.y The teeth onthe stator and rotor are progressively more and more non-alined betweenthe alined portions and the portions at right angles thereto, at whichlatter portions they are in complete staggered relation. It will be seenthat upon rotation of the rotor a distance equal to one tooth pitch onthe rotor, the alined portion of the teeth is gradually shifted aroundthe circumference of the rotor for an angular distance of 1800, therebycausingy the movement of the path of least magnetic reluctance forone-half a complete revolution for every angular' movement of the rotorfor one tooth pitch, or in other words, the axis of magnetizationbetween the stator and rotor makes one complete revolution for eachmovement of the rotor through twice a tooth pitch. Since the number ofteeth on the rotor is greater than the number on the stator, therotation of the axis `of magnetization is in the same direction as thatof the rotor. and it is apparent that its rotation would be in theopposite direction if the number of teeth on the stator was greater thanthe number on the rotor. Thus, the rotation of the rotor produces arevolving magnetic field in inductive relation to the winding. Eachrevolution of the magnetic field induces two complete cycles in thewindings, but since the revolving field travels in the same direction asthe rotor, the windings on the inductor, since they follow theprogression of the magnetic lield, are cut by the alternating ield onlytwenty-nine times, instead oi thirty-one times, or in other words, thereare twenty-nine complete cycles of current induced in the windings foreach rotation of the rotor. rlhe number of cycles per revolution ofgenerated current in the inductor windings is equal to the number oflteeth on the rotor minus the number of alined portions in a machine inwhichthe field rotates in the same direction as the rotor and is equalto the number of teeth on the rotor plus the number o'f' alined portionswhen the field rotates in the opposite direction to the rotor. Thedirection of rotation of the field with respect to the direction ofrotation of the rotor is determined by the direction of rotation of thealined portion. In the machine shown in Fig. 2 there are two more teethon the rotor than on the stator so that the alined portion rotates inthe same direction as the rotor, but if there were two more teeth on thestator than on the rotor, the alined portion would rotate in theopposite direction to the rotor. In the present construction there aretwentynine coils in the armature winding, or as many coils as there arecycles of generated current.

In order to commutate the current thus generated, the winding isprovided with a number of taps Or leads, which are connected to thecommutator segments. The commutator is divided circumterentially into aplurality of insulated segments, and the number of segments withrelation to the number of coils determines the character of the current.If the number of commntator segments equals the number of cycles otcurrent induced in the coils by each rotation of the rotor`r the currentdelivered to the commutator brushes will be a direct current. It' thenumber of commutato-r segmentsy be increased or decreased from thenumber of cycles per revolution of the inductor, the neutral points onthe commutator will gradually get ahead of or tall behind the revolvingmagnetic field, resulting in a slowly alterating current in thecommutator brushes. The brushes Contact with the commntator at neutralpoints.. The number of brushes which are employed in order` to cause thepoint of contact or commutation to travel in the same direction as thefield must be less than the number of segments on the comniutator andthe difference in number is determined by the number of alined portions,and when the point of commutation is to travel in the opposite directionfrom the eld the number of brushes is greater bythe same number. Thepositive and negatire brushes are s0 yarranged that when a currentpasses from them to the connnutato-r segn'ients and thence to thearmature windings, the current will produce a magnetomotive force whichwill neutralize the field flux on one side of the middle of the alinedportion and will have the same direction as that of the iield iiuX onthe other side ot the middle, as is indicated in4 Fig. 2. On each sideof the center line or middle there is produced a positive polarity (N)by the field current, whereas the current in the armature windings willproduce a negative polarity (S) on one side and a positive polarity onthe other side of the middle line, tending to neutralize the iield fluxon one side and increasing it on the other, whereby a torque is producedwhich causes the rotor to revolve toward the `side at which the flux isincreased.

In the construction diagraminatically illustrated in Figs. 4, 5 and 6,omitting for the present the alternating current connections, I haveshown twenty-nine .regularly spaced commutator segments i8 andtwentysev'en regularly spaced positive brushes i8, all connectedtogether, and twenty-seven regularly spaced negative brushes 19, allconnected together. The planes of the two sets of brushes are axiallyalined and both sets of brushes engage the commutator segments. Onaccount of the difference in number of the brushes in Leach set and thenumber of segments on the commutator, there are two positionsdiametrically opposite each other at which the brushes in either setAare fully alined or in contact with the commntator segments, and twodiametrically opposite portions, half way between the alined orcontacting portions, at which the brushes are staggered with relation tothe commutator segments. Between the alined or contacting portions andthe staggered portions the distances between the brushes and thesegments vary, increasing from the alined position to the staggeredposition. The negative brushes 19 are so arranged with relation to thepositivo brushes 18 that the plane of alinement of the negative brushesand the segments occurs at an angle of 90 degrees from the plane ofalinement of the positive brushes and the commutator segments. Withreference to the teeth on the stator and rotor, the posi tive brush isin contact with the segment which is connected to the coil whichsnrrounds the kalined portion, and the negative brush is in contact withthe segment which is connected to the coil which surrounds the portionof maximum non-alinen'ient. Mechani cally considered, the brushes mayhave any position with respect to the alined and non-alined portionsdepending upon the ar angement of the leads from the coils to thesegments. The angle between the points of full ycontact of the positiveand negative brushes is the same as the angle between the fully alinedand ncn-alined teeth on the stator and rotor. The point ot contact ofbrush and segment moves at the same rate ot progression as the teld.thereby causing the point ot contact to maintain its neutral positionwith respect to the iield. The current entering the commutator from apositive brush passes through the coils ot' the armature windingintervening between the positive brush and the negative brush.

It is not essential in order to produce the required progression of thepoint of contact ot brush and segment at the same angular velocity asthe iield that the number of brushes employed be equal to the number ofsegments minus the number of portions of tooth alinement. In Figs. T, 8and 9 I have shown a construction in which only nine positive brushesand nine negative brushes are employed, this being accomplished byemploying a number of brushes equal to onethird of the number ofcommutator segments minus the number of portions of tooth alinement. inthe present instance (Ql-2i-Z-S:9. The brushes in each set are connectedtogether and are regularly spaced, and the sets are arranged withrelation to each other in the same manner as the sets in theconstruction shown in Figs. l. 5 and 6. Similar results are obtained bythis construction with the exception that the point of contact jumps toeach third segment instead ot to the adjacent segment. In thisarrangement also the points of alinement or contact oi' the segments andbrushes in each set are not di ametrically opposite since two brushesare in contact with the segments on one side of the commutator and onlyone brush on the other side. lout the effective result is the same.

In the constructions shown in Figs. 4 to 9 inclusive two sets ofbrushes. each set eX- tending completely around the commutator, areemployed. the brushes in each set inaking` contact with the commutatorsegments at diametrically opposite portions. This arrangement permitsthe employment of a multiple winding in a tour pole machine. A machinein which the stator and rotor teeth are alined at two portions is a fourpole machine. two ot the poles being formed at the alined portions andtwo at the nonalined portions. The coils of the armature winding mayhave a full or fractional pitch. but the spacing is substantially thatof a tour pole machine.

By employing a series winding, illustrated in and' 3. in which thecurrent passes trom one coil to a coil diametrically opposite. thence tothe coil adjacent the first coil and thence to the coil diametricallyopposite and so on. the number of brushes may be t'urther decreaseditbout varying from the results obtained. In this construction thepositive brushes 18 are arranged around one-halt of the commute-tor andthe negative brushes 19 are arringed around the other half of thecommutator, the brushes being arranged so that at least one positivebrush and one negative brush is always in contact with the commutatorsegments. In the construction shown in Fig. 3. I have employed fiveregularly spaced positive brushes and tive regularly spaced negativebrushes which are so arranged with relation to the commutator segments,that current flows through w the proper coils of the armature winding,producing torque as above described.

lVhen it is desired to provide a machine which will produce or consumean alternating current of low frequency, the number of coils commutatorsegments and brushes is varied. In the present construction I have showna stator provided with twenty-nine teeth and a rotor provided withthirty-one teeth, such an arrangement operating to induce a current oftwenty-nine cycles per revolution in the armature winding. In order toobtain a direct current I employ twentynine coils in the armaturewinding and twenty-nine commutator segments. Should the number of coilsbe increased to thirtyone and the number of segments to thirtyone, andthe number of brushes to twentynine, the neutral points on thecommutator will gradually get ahead of the revolving magnetic field,resulting in this instance in a current having a frequency of two cyclesper revolution. IVhen it is desirable to retain the same commutatorsegment and brush relation that is shown in Figs. 3 to 9, a lowfrequency alternating current may be produced by providing a machinehaving a different number of stator teeth, rotor teeth and coils. In theconstruction shown in Fig. 10. I have employed a stator havingtwenty-seventeeth` a rotor having twentynine teeth and a series armaturewinding having twenty nine coils, such construction operating to inducea current of twenty seven cycles per revolution in the armature winding,and since there are twenty-nine commutator segments, the neutral pointson the commutator will gradually drop behind the revolving magneticiield. resulting in an alternating current of low frequency at thebrushes. The number yof cycles in the generated current is equal tothedifference between the number of segments in the commutator and thenumber of cycles per revolution produced in the armature winding,whether there is a greater or a less number ot' cycles .per revolutionthan there are commutator segments.

This machine may also be used as a converter and may be employed tovariously convert the character of the current delivered to it. It maybe arranged to convert trom direct current to high frequency alternatingcurrent and vice versa, and it may be employed to convert high frequencyalternating vcurrent and vice versa. ranging collector rings 23, 24, 25on the rotor or rotor shaft, insulated from each other and from theshaft, and properly connecting these rings with the armature winding, asshown in Fig. 5, or any other suitable manner, alternating current maybe fed to or taken from the collector rings. The introduction of analternating current into the collector rings, and the synchronousrotation of the rotor as determined by the supplied frequency, willresult in a direct current at the commutator brushes if the constructionof the machine is such that, acting as a generator, direct current isproduced at the commutator brushes. This direct current construction isshown in the drawings and has been described heretofore. If in suchconstruction direct current is supplied to the commutator, alternatingcurrent is produced at the collector rings, the frequency of thealternating current depending upon the speed of the rotor.

If the arrangement of windings, commutator segments and brushes is suchthat when acting as a generator, low frequency alternating current isproduced, at the commutator brushes, and alternating current of highfrequency is supplied to the collector rings, an alternatingy current oflow frequency is obtained at the commutator brushes. 1f low frequencycurrent is supplied to the eommutator and the rotor rotated insynchronism with the supplied current, ya high frequency current isproduced at the collector rings.

Instead of arranging the armature winding on the rotor, the winding maybe arranged on the stator, in which case the commutator will bestationary and the commutator brushes mounted on and revoluble with therotor shaft, or the windings may be connected to the brushes and thecommutator revolve with the rotor or the armature winding may bearranged on both stator and rotor.

lVhen the machine is constructed to produce an alternating current atthe commutator this current may be collected as a single phase current,or as a two phase current, or as a three phase current. In Fig. 11 1have shown a series wound machine arranged for the collection of twophase current. The brushes of one phase 31 32 are arranged similarly tothe brushes in 3, and the brushes of the other phase 33-34 are arrangedadjacent the brushes 31m-32 and spaced from them a distance equal toone-fourth the distance between the brushes 3l or 32. In Fig. 1Q I haveshown a three phase arrangement in combination with a series winding.The brushes 35 are in the same relative position as the upper set el'brushes in Fig. 3 and the brushes 36 and 37 are evenly spaced between.the brushes By ar- When a series winding is employed the three lowerseries of brushes may be dispensed with. f n

From the above, it will be seen that this machine possesses greatflexibility, and among other uses may be employed for the followingpurposes: (l) An alternating current, single or polyphase, highfrequency per revolution, generator or synchronous motor, in which casethe current is taken oil' from or supplied to the collector rings.

An alternating current, single or poly-` phase, low frequency perrevolution, generator or synchronous motor, in which case current istaken from or supplied to the commutator brushes. (3) Direct currentgenerator or motor, in which case the current is taken from or suppliedto the brushes on the commutator. (4) Alternating current commutatingmotor, in which use the current is supplied to the brushes on thecommutator. (5) To convert alternating current, single or polyphase,having a high frequency, to an alternating current single or polyphase,having a low frequency, in which case the current is impressed at thecollector rings and delivered at the commutator brushes. To convertalternating current, single or polyphase, havingr a low frequency, to analternating current single or polyphase, having a high frequency, inwhich the current is impressed at the commutator brushes and deliveredto the collector ring brushes. (7) To convert alternating current,single or polyphase, ha v'- ing a high frequency, to a direct current,in which use the current is impressed on the collector rings anddelivered at the commutator brushes. (8) To convert direct current intoalternating current, single or polyphase, having a high frequency perrotation of the inductor, in which use the current is impressed at thecommutator brushes and delivered at the collector rings.

The output relative to the weight of this machine, as a generator ormotor, is very great due to the high velocity with which the magneticfield revolves, thereby cutting the winding ofy the inductor, but itwill be readily understood that its output is considerably greater whenused as a rotary converter, since only a portion ofthe impressed currenttraverses the winding, the rest passing directly from the brushes on theconimutator to the collector rings, or vice versa.

The efficiency of such a machine in case of a generator or motor, islikewise very high on account of the small amount of iron and copperrequired in proportion to its output, and its efficiency is much higherin case of the converter, by reason of its greatly-r increased capacityas above explained.

I claim:

1. In a dynamo electric machine of the commutating type, a toothedstator, a

toothed rotor, an armature winding and commutating means comprising aseries of of rotatable conducting elements, and a series of stationaryconducting elements, said two series of elements being arranged toproduce a progression oi' the point of Contact between the elements otthe two series with relation to the stationary and rotatable elements,said armature winding being connected to one of said series ofconducting elements.

2. In a dynamo electric machine of the commutating type, a toothedstationary element, a toothed rotatable element, means including saidelements for producing a rapidly revolving magnetic field having agreater angular velocity than said rotatable element, an armatureWinding in inductive relation with said field, and commutating meanscomprising a series of rotatable conducting elements and a series ofstationary conducting elements, said two series of elements beingarranged to produce a progression of the point oi' Contact between theelements of the two series with relation to the rotatable conductingelements, said armature winding being connected to one of said series ofconducting elements.

3. In a dynamo electric machine of the commutating type, a stationaryelement and a rotatable element, means including said rotatable elementfor producing a rapidly revolving magnetic iield having a greaterangular velocity than said rotatable element, an armature winding ininductive relation with said iield, and commutatingv means comprising aseries of rotatable conducting elements and a series of stationaryconducting elements, the armature winding being connected to theelements of one of Said series, said two series of elements beingarranged to produce a progression of the point oi contact between theelements of the two series, with relation to the rotatable conductingelements.

l. In a dynamo electric machine of the commutating type. a rotatingelement, an armature winding, means including said rotating element forproducing a rapidly revolving magnetic field having a greater angularvelocity than said rotating element in inductive relation to saidwinding, and commutating means comprising a series of rotatableconducting elements and a series of stationary conducting elements, saidtwo series of elements being arranged to produce a progression of thepoint of contact between the elements of the two series with re lationto the stationary conducting elements, said armature winding beingconnected to one ot' said series of conducting elements.

In a dynamo electric machine 4of the commutating type, toothed stator, atoothed rotor, an armature Winding and commutating means comprising aseries of conducting elements connected to the armature winding, and aseries of conducting elements relatively movable with respect to `theother series and arranged so that one tire periphery differing in numberfrom those on said stator, an armature winding andv commutating meanscomprising a series of conducting elements equal in number to the statorteeth connected to said winding, and a series of conducting elementsrelatively rotatable with respect to the irst series.

7. In a dynamo electric machine of the commutating type, a toothedstator, a rotor having teeth spaced regularly around its entireperiphery, differing in number from those on said stator, an armaturewinding and commutating means comprising a series of conducting elementsequal in number to the coils of the winding connected to said winding,and a series of conducting elements relatively rotatable with respect tosaid iirst named elements, and arranged to produce a progression of thepoint of contact between the elei ents of the two series with relationto the stator.

8. In a dynamo electric machine of the connnutating type, a toothedstator, a rotor having teeth spaced regularly around its entireperiphery, diering in number from those on said stator, an armaturewinding having as many coils as there are stator teeth', and commutatingmeans comprising a series of conducting elements equal in number to thecoils of the winding and individually connected thereto, and a series ofconducting elements relatively movable with respect to said firstseries, the number and arrangement of the elements in the second seriesbeing such as to produce a progression of the point of contact betweenthe elements of the two series with respect to the rotor.

9. In a dynamo electric machine ofthe commutating type, a regularlyspaced toothed stator, a rotor having a different number of regularlyspaced teeth than the stator, an armature winding having as many coilsas there are teeth on the stator, and commutating means comprising aseries of regularly shaped insulated conducting elements equal in numberto the number of coils in the armature winding and connected to saidcoils, and two series of conducting elements arranged to engage saidfirst named series, the number and spacing of the ele ments comprisingeach of the two series being such as to produce a. progression of thepoints of contact between the elements of the iii-st series and theelements of the two second series with relation to the rotor.

10. In a dynamo electric machine ot the commutating type, a regularlytoothed stator, a regularly toothed rotor, the angular pitch of thestator and rotor teeth being different, and armature winding having asmany coils as there are stator teeth, a commutator having as many activesegments as there are stator teeth., the coils of the wind ing beingconnected to said segments and a plurality of brushes engaging saidcommutator, the number and spacing of the brushes being such as toproduce a progression of the point of contact between the brushes andthe segments with relation to the stator and rotor.

11. In a dynamo electric machine of the con'nnutating type, an armaturewinding comprising a plurality of coils, a rotatable element, meansincluding said element for producing a revolving magnetic ield ofgreater angular velocity than said element in inductive relation to saidwinding, a commuta tor having as many active segments as there are coilsin said winding connected to said coils, and a plurality of stationarybrushes engaging said commutator, the number and spacing of the brushesbeing such as to produce a progression of the point of contact betweensaid brushes and commutator around the commutator.

l2. In a dynamo electric machine of the connnutating type, a toothedstator, a toothed rotor, an armature winding comprising a plurality ofcoils, a commutator having as many active segments as there are coils insaid winding, said segments being connected to said coils, and twoseries of brushes engaging said commutator, one series oiI brushes beingpositive and one series being negative, the brushes in each series beingarranged to produce a progression of the point of contact of brush andsegment with relation to the rotor.

13. In a dynamo electric machine of the commutating type, a toothedstator, a toothed rotor, an armature winding, alter-V nating currentconductors connected to said winding and commutating means comprising aseries of rotatable conducting elements, and a series of stationaryconducting elements, said two series of elements being arranged toproduce a progression of the point of contact between the elements ofthe two series with relation to the rotatable conducting elements, saidarmature winding being connected to one of said series of conductingelements.

14;. `In a dynamo electric machine of the commutating type, atoothedstationary element and a toothed rotatable element, means segmentsincluding said elements for producing a revolving magnetic iield havinga greater' angular velocity than said rotor, an armature winding ininductive relation with said field, alternating current conductorsconnected to said armature winding and commutating means comprising aseries of rotatable conducting elements, and a series of stationaryconducting elements, said two series ot elements being arranged toproduce a progression of the point of contact between the elements otthe two series with relation to the stationary and rotatable conductingelements, said armature winding being connected to one ot said series otcon ducting elements.

15. In a dynamo electric machine ot the commutating type, a toothedstator, a toothed rotor, an armature winding, alternating currentconductors connected to said winding and commutating means comprisingtwo series oi". conducting elements, one of said series being rotatablewith respect to the other, the number and spacing of the elements insaid two series being such as to produce a progression of the point otcontact between the elements et the two series with respect to thestator and rotor, and means connecting the elements oi' one of saidseries with the armature winding.

16. In a dynamo electric machine of the commutating type, a rotatingelement, an armature winding, means including said rotating element forproducing av rapidly reA volving magnetic iield having a greater angularvelocity than said rotating element in inductive relation to saidwinding, alternating current conductors connected to said winding andcommutating means comprising a series or rotatable conducting lements,and a series of stationary conducting elements, said two series oi'elements being arranged to produce a progression of the point of contactbetween the elements oi' the two series with relation to the stationaryconducting elements, and means connecting the armature winding to one ofsaid series of conducting elements.

17. In a dynamo electric machine of the commutating type, a regularlytoothed sta-l tor, arotor having regularly spaced narrow teeth, anarmature winding, altefnating,` current conductors connected to saidwinding and commutating means comprising a series of conducting elementsconnected to the armature winding, and a series of conducting elementsrelatively movable with respect to the other series and arranged so thatone of the elements in one series is always in contact with one of theelements in the other series, and so that said point of contactprogresses with relation to the rotor.

18. In a dynamo electric machine of the commutating type,a toothedstator, a rotor having regularly spaced narrow teeth diflli) tering innumber from the teeth on said stator, an armature winding, alternatingcurrent conductors connected to said winding and commntating meanscomprising a series ol conducting elements equal in number to the statorteeth connected to said winding, and a series oi' conducting elementsrelatirely rotatable with respect to said irst series.

19. In a dynamo electric machine of the commutating type, a toothedstator, a rotor haring regularly spaced narrow teeth ditfering in numberfrom the teeth on said stator, an armature winding comprising aplurality ot coils, alternating current conductors connected to saidwinding', and commutating means comprising a series of conductingelements equal in number to the 'coils of the winding connected to saidwinding, and a series of conducting elements relatively rotatable withrespect to said first named elements and arranged to produce aprogression of the point of contact between the elements ot the twoseries with relation to the rotor` 20. In a dynamo electric machine ot'the commutating type, a toothed stator, a rotor having regularly spacednarrow teeth diftering in number from the teeth on said stator, anarmature winding ha -ing as many coils as there are teeth on the stator,alternating current conductors connected to said coils and commutatingmeans comprising a series of conducting elements equal in number to thecoils of the winding and individually connected thereto, and a series oiconducting elements relatively movable with respect to said iirstseries, the number and arrangement oit' the elements in the secondseries being such as to produce a progression ot the point of contactbetween the elements ot the two series with respect to the rotor.

2l. ln a dynamo electric machine ot' the commutating type, a toothedstator, a rotor having a different number of teeth than the stator, anarmature winding haring as many coils as there are teeth on the stator,alternating current conductors connected to said winding and commutatingmeans comprising a series oi insulated conducting elements regularlyspaced and equal in number to ,the number of coils in the armaturewinding and connected to said coils, and two series of conductingelements arranged to engage said first named series, the number andspacing of the elements in each of the said two series being such as toproduce a progression of the points oi' contact between he elements ofthe lirst series and the elements of the two second series with relationto the rotor.

QQ. In a dynamo electric machine of the commutating type, a toothedstator, a rotor haring a ditferent number of teeth than said stator, anarmature winding having as many coils as there are stator teeth,alternating current conductors connected to said winding, a commutatorhaving as many active segments as there are stator teeth, and aplurality ot brushes engaging said commutator, the number and spacing ofthe brushes being such as to produce a progression of the point ofcontact between brushes and segments with relation to the rotor.

23. In a. dynamo electric machine of the cominutating type, an armaturewinding comprising a `plurality of coils, alternating current conductorsconnected to said winding, a rotatable element, means including saidelement for producing a revolving magnetic lield of greater angularvelocity than said element in inductire relation to said winding, acommutator in iixed relation to the rotatable element having as manyactivo segments as there are coils in said winding connected to thesegments, and a plurality of stationary brushes engaging saidcommutator, the number of brushes being such as to produce a progressionof the point of contact between said brushes and commutator segmentsaround the commutator.

2l. In a dynamo electric machine ot' the commutating type, a series ofrotatable conducting elements and a series of stationary conductingelements, said two series ot ele ments being arranged to produce aprogression of the point of contact between the elements of the twoseries with relation to the elements of the two series.

In testimony whereof, I have hereunto set my hand at San Francisco,California, this 2nd day of July, 19M.

ALFONS H. NEULAND.

In presence ot- H. G. PRosT,

J. B. GARDNER.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents, Washington, D. C.

